a workflow-based architecture for e-learning in the grid

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CLAG 2004 – April/04 1 A Workflow-based Architecture for e-Learning in the Grid Luiz A. Pereira, Fábio A. Porto, Bruno Schulze, Rubens N. Melo {lpereira,rubens}@inf.puc-rio.br, {fporto,schulze}@lncc.br

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A Workflow-based Architecture for e-Learning in the Grid. Luiz A. Pereira, Fábio A. Porto, Bruno Schulze, Rubens N. Melo {lpereira,rubens}@inf.puc-rio.br, {fporto,schulze}@lncc.br. Agenda. Introduction/Motivation Description of the Environment Description of the Architectural Model - PowerPoint PPT Presentation

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CLAG 2004 – April/04 1

A Workflow-based Architecture for e-Learning in the Grid

Luiz A. Pereira, Fábio A. Porto, Bruno Schulze, Rubens N. Melo{lpereira,rubens}@inf.puc-rio.br, {fporto,schulze}@lncc.br

CLAG 2004 – April/04 2/21

Agenda

Introduction/Motivation

Description of the Environment

Description of the Architectural Model

Related and Future Works and Concluding Remarks

CLAG 2004 – April/04 3/21

Introduction/MotivationMotivation: PGL (Partnership In Global Learning) Project

(PUC/UF) Many partners providing learning content in a global scale:

data distribution, technological heterogeneity, easy and cost effective content access.

e-Learning scenarios requiring computational-intensive learning objects for simulation purposes (LNCC) Fluid mechanics course containing the simulation of a fluid

path, which requires the computation of virtual particles trajectories (applied to hemodynamics)

CLAG 2004 – April/04 4/21

Introduction/Motivation

Requisites: Effective e-learning environments should promote high

cooperation. Benefits: in the cognitive domain, improving learning capacity and academic

performance. in social and affective ones – improving group and individual self-

confidence. It is important to consider new methods to reduce learning content

development costs. It is also important to consider (cost) effective content delivery

mechanisms. Many cases requiring massive computing power and/or data

storage usually not available in a single workstation.

CLAG 2004 – April/04 5/21

Introduction/MotivationProposed Solution: Cooperation WfMS, providing:

Executor-task assignments Effective interaction coordination Execution duration control and synchronization Coordination of the execution of tasks involving massive

computation and/or data processing. Content development cost reduction use of modular

and reusable learning modules (LOs): To facilitate deployment and execution assignment Reusability and standardization contributing to content

development costs reduction and quality improvement.

CLAG 2004 – April/04 6/21

Introduction/Motivation Proposed Solution(cont.):

(Cost) effective content delivery mechanisms Web based environment

Massive computing power and/or data storage Grid

CLAG 2004 – April/04 7/21

Introduction/Motivation

TEAM is both An architectural model: Teamwork-support

Environment Architectural Model Operating environments based on the

architectural model: Teamwork Applications Manager

CLAG 2004 – April/04 8/21

Introduction/Motivation

TEAM (the architectural model): TEAMA

TEAM (the environment): TEAME, instantiated to e-learning.

CLAG 2004 – April/04 9/21

Description of TEAME

Students and teachers would execute instructional steps cooperatively guided by a WfMS

WfMS deals transparently with distribution, autonomy and technological heterogeneity of the content repositories that are located in the partners’ sites

Content is LO-oriented and is described using the IEEE-LOM standard.

CLAG 2004 – April/04 10/21

Description of TEAME

The processing unit of the environment is called a peer, working as a gateway to environment Provides user’s authentication, User-environment interaction control, Execution context management.

Each user is associated to a peerA site is a logical collection of peers sharing a common learning purposeUsers have transparent access to resources within sites in which his home peer is included

CLAG 2004 – April/04 11/21

Description of TEAME

The environment is logically divided in two scopes, external and internal, according to user roles.

CLAG 2004 – April/04 12/21

Description of TEAME

The external scope: Provides an environment for students accessing

courses they are registered to attend. External users “see” the (distributed)

environment as just one piece The workflow enactment services provide this

transparent vision to external users, routing, retrieving and allocating resources to/from proper peers

CLAG 2004 – April/04 13/21

Description of TEAME

The internal scope: Refers to the working context of the

environment’s the internal users: Technical support staff, Application developers, Database administrators and Learning content developers

CLAG 2004 – April/04 14/21

Description of TEAME

The distributed e-learning environment scopes

Peer 1

Peer 2

Peer 4

Peer 3

Internal Users

External Users

Internal Users

CLAG 2004 – April/04 15/21

Description of TEAME

What about content? It is LO-oriented Developed in “reusable modules” from scratch

and/or Developed by aggregating LOs developed by

other partners Lightweight or Heavyweight, requiring Grid resources

CLAG 2004 – April/04 16/21

Description of TEAMA

Architecture based on mediator(s) and wrappersPeers are functionally identical but some of them run on top of a grid (operating) system to access resources provided by grid environment(s).Grid resources management to be done transparently from the user perspective

CLAG 2004 – April/04 17/21

Site 1Site 2

Site 3Site 4

P1 P2 P3

P4P5P6

Grid 1

Grid 2

Description of TEAMA

TEAMA conceptual view

TEAM Connection

Grid Connection

CLAG 2004 – April/04 18/21

Description of TEAMA

Each peer in TEAMA is a stack of three layers (a 3-tier architectural model) User Interface, Workflows services (business processes/rules) Other services (data persistence, resource

scheduling, …) .

CLAG 2004 – April/04 19/21

Description of TEAMA

TEAM 3-tier architecture

User interface with the environment:a web browser or a .NET application.

The functional core of the architecture:The workflow enactment service managing a convenient portion of the whole workflow instance.

Service layer provides data persistenceand grid access for heavyweight tasks.

ApplicationApplicationBrowserBrowser

User associated to site i

Web services for data sources access

Web services for data sources access

Control

Data

Metadata

JSPJSP

Web services

Workflow enactment service

Grid

CLAG 2004 – April/04 20/21

Related and Future Works and Concluding Remarks

At LNCC we are developing a grid infrastructure to be used transparently from several kinds of applications.

One of these types of applications is an e-Learning Management System capable of sharing distributed e-learning modular content and controlling student-student and student-teacher collaboration.

CLAG 2004 – April/04 21/21

Related and Future Works and Concluding Remarks

TEAM extension towards its integration with grid infrastructure is at its initial phase. We need to integrate user authentication between

TEAM and the grid We need to develop a more refined authorization policy

that will include information on user rights to access a LO

We need to extend our current LO storage and query services

We need to refine how our search for LOs will be implemented

We need to improve workflow specification to work on a non-structured scenario